Microelectronics packages, called hybrids or multi chip modules, utilize unpackaged semiconductor dice. Because of an increased use of hybrids, semiconductor manufacturers are required to supply unpackaged dice that have been tested and certified as known good die (KGD). A known good die (KGD) is an unpackaged die having the same reliability as the equivalent packaged die.
The need for known good dice has led to the development of test apparatus suitable for testing unpackaged semiconductor dice. As an example, test apparatus for conducting burn-in tests for unpackaged dice are disclosed in U.S. Pat. Nos. 5,302,891; 5,408,190 and 5,483,174 to Wood et al., which are assigned to Micron Technology, Inc.
With this type of test apparatus, a non-permanent electrical connection must be made between contact locations on the die, such as bond pads, and external test circuitry. The bond pads provide a connection point for testing the integrated circuits formed on the die. The test apparatus typically includes some type of interconnect having a pattern of contact members for effecting the temporary electrical connection to the bond pads on the die.
In making this temporary electrical connection, it is desirable to form a connection that causes as little damage as possible to the bond pads on the die. If the contact members for the interconnect damage the bond pads, the entire die may be rendered as unusable. This is difficult to accomplish because the contact members must also produce a low resistance or ohmic contact with the bond pads. It is also desirable for the contact members to accommodate dimensional variations in the bond pads, particularly variations in a z-direction. For this reason contact members for interconnects are sometimes constructed as flexible or compliant members that can move up or down upon contact with the bond pads.
In view of the foregoing, it is an object of the present invention to provide an improved compliant contact system for making temporary electrical connections to unpackaged semiconductor dice and a method for fabricating the compliant contact system. It is yet another object of the present invention to provide an improved compliant contact system for testing unpackaged semiconductor dice that can be fabricated out of silicon using semiconductor circuit fabrication techniques. It is a further object of the present invention to provide an improved compliant contact system that includes an interconnect with raised contact members and an alignment fixture for mechanically aligning contact locations on the die with corresponding contact members on the interconnect. Other objects, advantages and capabilities of the present invention will become more apparent as the description proceeds.